Hard-disk drives use one or more disks or platters that rotate about a spindle with respect to one or more heads, such as read and/or write heads. The read or write heads read information from or impart information to the disk platters, but do not, in desired operation, physically contact the platters. To the contrary, HDD heads are suspended above the spinning platters.
To adjust head position (e.g., height) relative to the disk surface, thermally sensitive material is used in the head. The thermally sensitive material expands and contracts based on head temperature and, therefore, changes the position of the head relative to the disk. Known systems monitor and control head temperature and make assumptions regarding head position based on head temperature.